Race, sex, and the regulation of urine osmolality: observations made during water deprivation
Bibliographic record
Abstract
A more concentrated urine is excreted by blacks than whites and by men than women. The purpose of this study was to explore the physiological bases for the race and sex effects during water deprivation when osmoregulation is challenged and differences are amplified. Drinking water was withheld from 17 blacks (10 men) and 19 whites (9 men) for 24 h. Vasopressin (VP) levels and osmolality in plasma (P(osmol)) and urine (U(osmol)) were measured basally and then every 4 h. U(osmol) was higher in blacks at baseline (P = 0.01) and during water deprivation (P = 0.046). Before and during water deprivation, no differences were seen in levels of VP, P(osmol), or the VP-U(osmol) relationship between blacks and whites. Although VP levels were initially higher in men (P < 0.02 for samples collected over the first 12 h), over the last 12 h of water deprivation, U(osmol) was higher (P = 0.027) and more responsive to the level of VP (in terms of slopes, P = 0.0001) in women than men. Our results suggest that, after a period of water deprivation, there develops a sensitivity of the collecting duct to VP that is greater in women. Although U(osmol) is higher in blacks, the race difference in water conservation did not appear to result from differences in the level of VP or the sensitivity of the collecting duct to VP. Upstream effects such as Na(+) uptake in the thick ascending limb, with its ensuing effects on water reabsorption, need to be considered in future studies of the relationship of race to water conservation.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".